Dartboard Problem

From Infinigons, etc: Putting myself in kids’ shoes You have a square dartboard. What is the probability that a randomly-thrown dart will land closer to the center of the dartboard than to an edge? Superb problem. I took the lazy route. I made a python program to run 100,000 trials, and graph those trials on a […]

Car Talk Puzzler (The Colored Caps)

The newest car talk puzzler. Draw a diagram, it may help. Three men, Mr. White, Mr. Brown and Mr. Green, were in the habit of meeting in a local doughnut shop every morning for coffee and doughnuts. One morning as they were sitting at their usual table, Mr. White remarked, “Hey, will you look at […]

Car Talk Puzzler (Palindrome Mileage)

New Math Puzzler up this week: Tommy’s Drive to Work RAY: Tommy has a new car, it’s 19 years old. … It has one of those newfangled six-digit odometers. It can register as many as 999,999 miles.  So one fine morning last week, Tommy gets into his new car to drive to work. He fires up his […]

Circle of Differences Puzzle

Great article from the NY Times on the Danger of Praise, with an excellent puzzle included: Circle of Differences The numbers 1, 2, 3 and 4 are written at the corners of a large square.  At each step, at the midpoint of each side, write the positive (or absolute value of the) difference between the […]

Car Talk Puzzler: Math + English =

Car Talk has a new math puzzler up that mixes math and science: There Was an Old Man…RAY: I’m going to recite an equation and, from that, you are going to give me a limerick that consists of five lines. TOM: Does this limerick include Nantucket or the band at the Waldorf Astoria? RAY: No! Here it is. […]

Car Talk Puzzler: In Search for Bogus Coins

In Search of the Bogus Coins RAY: We have seven stacks of coins, each with 100 coins. Real coins weigh ten grams, and phony coins weigh 11 grams. We’re going to weigh the coins on an analytic scale, which works just like your average bathroom scale – but it’s accurate to within a tenth of a […]

Leaking Gasoline Puzzler

The Last Gasp of the Fiat “A car travels at a steady speed of 45 mph. Its fuel consumption is 30 miles to the gallon. It has a 15-gallon gas tank, which was full when the car started off. But at the very moment the car begins to move at 45 mph, the gas tank begins to leak […]

Three Slips of Paper – Car Talk Puzzler

Excellent probability (ish) puzzler from Car Talk: Three Slips of Paper RAY: This is from Norm Leyden from Franktown, Colorado. The date on it is 1974–I’m a little behind. Three different numbers are chosen at random, and one is written on each of three slips of paper. The slips are then placed face down on […]

Two Classic Puzzlers from Cartalk

Puzzler 1: Every two-digit number can be represented as AB, where B is the ones digit and A is the tens digit. Right? So for example the number 43, A is 4 and B is 3. Imagine then that you took this two-digit number and you squared it, AB x AB, and when you did […]

Two Great Puzzlers from Cartalk

1.  Cats, Dogs and Mice – Oh My! RAY: You’re given a hundred dollars and told to spend it all purchasing exactly a hundred animals at the pet store. Dogs cost $15. Cats cost a buck, and mice are 25 cents each. TOM: Let me get this straight. You have to spend exactly a hundred […]